Hydraulic presses

ABSTRACT

A press tool for forming pipes is constructed from multiple, parallelly arranged ram/cylinder arrangements wherein the ram remains stationary and the respective cylinders are hydraulically moved. The cylinders each carry an arcuate tool on their front end so that the work is engaged by plural tools in a row. The cylinders are tied together by transverse beams on opposite sides of each cylinder to compell common press action. The cylinders are moved towards lower tool holders of complementary configuration.

United States Patent [191 Snell 1 1 HYDRAULIC PRESSES [75] Inventor: Donald Noel Snell, Bournemouth.

England [73] Assignee: Mannesmann-Meer Aktiengesellschaft, Monchengladbach, Germany [22] Filed: Aug. 23, 1972 [21] Appl. No.: 283,167

[301 Foreign Application Priority Data Aug, 27, 1971 United Kingdom 1, 40308/71 [52] US. Cl 72/453; 72/455 [51] Int. Cl B2lj 9/12 [58] Field of Search 72/453, 455, 404, 405',

[56] References Cited UNITED STATES PATENTS 2,722,174 11/1955 Albers 1. 100/214 [451 July 1, 1975 2,860,571 11/1958 Hatch 100/214 3,037,446 6/1962 Thompson 100/98 R 3,393,635 7/1968 Richardson t 1 100/208 3,523,443 8/1970 Allen 72/453 Primary ExaminerC. W. Lanham Assistant ExaminerGene P. Crosby Attorney, Agent, or FirmRalf H. Siegemund [57] ABSTRACT A press tool for forming pipes is constructed from multiple, parallelly arranged ram/cylinder arrangements wherein the ram remains stationary and the respective cylinders are hydraulically moved. The cylinders each carry an arcuate tool on their front end so that the work is engaged by plural tools in a row. The cylinders are tied together by transverse beams on opposite sides of each cylinder to compel] common press action. The cylinders are moved towards lower tool holders of complementary configuration.

4 Claims, 3 Drawing Figures HYDRAULIC PRESSES This invention relates to hydraulic presses and has particular although not exclusive reference to pipeforming presses.

In one known method for the production of pipes for the transmission of gas, oil, etc., a workpiece in the form of a flat plate is deformed into a U-shape by a first press and then is transferred to a second and separate press where the U-shaped plate is further deformed into a O shape.

Known form press designs are of the laminated frame type in which a series of plate frames are tied together by suitable means. Each frame or sub-frame supports a fixed hydraulic cylinder having an associated moving ram attached to a common platen member or tool support which comprises a beam assembly in one or two parts. This platen member extends axially through the press and is adapted to carry the necessary press tools. In operation, the previously formed U- shaped plate is positioned under the platen member and within the stationary counter-member or bottom tool. The platen member is then advanced under power to deform the U-shape into an O-shape.

In these known designs the platen member has to be made a substantial structure having sufficient depth to withstand high bending stresses. The latter can occur, for example. when the length of the workpiece is less than the maximum possible, which is, of course, determined by the length of the press tools. In this case, the ends of the tools and tool supports will overhang the ends of the workpiece and consequently will not be reacted on by the workpiece during the deforming operation and will cause a bending moment to be applied to the platen member.

The massive size of the platen member not only results in a press structure of considerable height which is expensive and inconvenient to house but also difficulties are frequently encountered during manufacture of the platen member because its weight and size necessitate the use of very large machine tools and lifting facilities.

According to the present invention a press for the production of pipes includes a number of hydraulic cylinder/ram assemblies, each cylinder of which constitutes a press tool carrier or is adapted to support a press tool carrier and is movable for applying pressure to a workpiece, the cylinders being linked together for common movement.

Preferably, the cylinders are linked together by a beam assembly mounted on the sides thereof.

In one arrangement according to the invention, the beam assembly is constituted by a pair of elongate members keyed into recesses formed in opposed faces of the cylinders. Each member can be constituted by one or more plates, the width or depth of each of which is large in comparison to its thickness.

The invention will now be described in more detail, by way of example, with reference to the accompanying drawings which illustrate an O forming hydraulic press and of which:

FIG. I is a sectional elevation of the press along line AA of FIG. 2;

FIG. 2 is a part section along line 8-3 of FIG. I; and

FIG. 3 is a part section along line CC of FIG. 1.

Referring to the drawings, the press frame I incorporates a series of sub-frames comprised of a number of transversely disposed plates 2 held together in fixed spacial relationship by bolts 3 and diaphragms 4.

The press frame 1 is arranged to support a number of hydraulic cylinder/ram assemblies arranged in a row. The rarns 8 of these assemblies are fixedly secured in the press frame 1 by studs 5, nuts 6 and support plates 7, the rams being mounted against pressure distribution pads 9. The cylinders of these assemblies are movable and are constituted by block-like structures 10, suitable packing and sealing means ll being disposed between each ram and its corresponding cylinder. Hydraulic fluid is passed, in use, through suitable connections l4 and passageways 15 to effect movement of the cylinders towards the fixed lower tool support 2]. Reverse movement of the cylinders is achieved by return cylinders 12 which are suspended from suitable fixed supports 13.

As will be seen from the drawings, the cylinders 10 are linked together and maintained in alignment by beam assemblies indicated generally at 16 which are keyed into recesses 17 formed in opposed faces of the cylinders. In the drawings, each beam assembly comprises two elongate, longitudinally extending plates but one or three or more such plates such as 16a, 16b could be employed. When two or more plates are used, they are secured together by suitable means such as tie bolts, not shown. To facilitate assembly and to ensure accurate alignment of the cylinder recesses 17 in the several cylinders, adjustable packing means 18 are provided in each recess. The beam assemblies not only ensure that the cylinders with tool execute common movement towards and away from the workpiece but provide the necessary longitudinal stiffness of the press. It is envisaged that the cylinders could be linked in other ways, for example, by providing connecting elements between the opposing faces of adjacent cylinders, but the use of plates along the sides of the cylinders as described above is preferred because this is a very simple and effective method of providing the necessary strength and rigidity of the moving parts of the press.

Each cylinder block is provided with a tool-holding recess 19 which is adapted to receive a shaped tool 20 for the metal working operation. The tool is retained in position within the recess by holding means, not shown. In an alternative arrangement, the tool carrying recess is not formed as an integral part of the cylinder but is machined in a separate block which is subsequently secured to the free end of the cylinder. A tool 22 adapted to cooperate with the tool 20 is mounted in the fixed lower support block 21.

It will be evident that the press construction described and illustrated above has considerable advantages over the conventional arrangement having moving rams and a common massive platen member. Thus, using the cylinders themselves as the moving parts and as the tool support effectively removes the need to use a massive platen member. Thus, the latter can be replaced by side beams or plates. This gives rise to four main advantages. Firstly, the piece weights can be significantly reduced. Thus, in one contemplated design, the laminated side plates described and illustrated individually weigh about 45 tons, whereas a traditionally designed tool support beam or platen member for the same press may weigh up to 300 tons. As a result, handling and erection of the press parts is significantly simplified. Secondly, manufacture of the cylinder blocks and machining of the tool carrying recesses is much simpler than manufacture and machining of the platen member. Thirdly, by securing the plates along the sides of the cylinders, the lenghts of each cylinder is usefully employed and, consequently, there is an overall reduction in press height compared to the conventional press Finally, and fourthly, the depth or width of each plate is significantly larger than the corresponding dimension of the conventional platen member and consequently, there is a marked improvement in the resistance to bending of the tool support during operation.

What we claim is:

1. In a press for the production of pipes, wherein the several parts are mounted in a frame the improvement comprising:

means defining a first shaped tool in the frame;

a plurality of parallelly disposed hydraulic cylinder/- ram assemblies, each of the rams being mounted in stationary disposition in the frame and hydraulically cooperating with the cylinder of the respective assembly for moving the respective cylinder towards the first tool upon application of hydraulic pressure to the cylinder;

each cylinder constructed to support a second press tool facing the first tool; and

means for interconnecting the cylinders of the assemblies to obtain alignment of the second tools in direction transverse to the direction of cylinder movement and to obtain common movement in the alignment disposition upon application of hydraulic pressure to the cylinders of the assemblies.

2. A press as set forth in claim I in which each beam has more than one superimposed plates with a width larger than its thickness.

3. A press as set forth in claim 1, wherein the means for interconnecting includes at least two beams mounted respectively on opposite sides of the cylinders.

4. A press as set forth in claim 3, wherein the cylinders have recesses into which the beams are keyed. 

1. In a press for the production of pipes, wherein the several parts are mounted in a frame the improvement comprising: means defining a first shaped tool in the frame; a plurality of parallelly disposed hydraulic cylinder/ram assemblies, each of the rams being mounted in stationary disposition in the frame and hydraulically cooperating with the cylinder of the respective assembly for moving the respective cylinder towards the first tool upon application of hydraulic pressure to the cylinder; each cylinder constructed to support a second press tool facing the first tool; and means for interconnecting the cylinders of the assemblies to obtain alignment of the second tools in direction transverse to the direction of cylinder movement and to obtain common movement in the alignment disposition upon application of hydraulic pressure to the cylinders of the assemblies.
 2. A press as set forth in claim 1 in which each beam has more than one superimposed plates with a width larger than its thickness.
 3. A press as set forth in claim 1, wherein the means for interconnecting includes at least two beams mounted respectively on opposite sides of the cylinders.
 4. A press as set forth in claim 3, wherein the cylinders have recesses into which the beams are keyed. 